Display device

Abstract

An object of the present invention is to provide a display device which enables multi-gray scale display without complicating the structure of D/A converter circuit. The measure taken to achieve the object is to use n bit of information among m bit digital video data inputted from external for voltage gray scale method, and (m−n) bit of information for time ratio gray scale.

1. A driving method of a display device comprising:
 converting n bit digital video data of m bit digital video data into n bit digital video data for voltage gray scale; and 
 expressing gray scale by using n bit data for voltage gray scale information and (m−n) bit data for time ratio gray scale information, 
 wherein each of a voltage level for the voltage gray scale is as (VH−VL)/2 n , where VH is the highest voltage level of voltages inputted to a D/A converter circuit and VL is the lowest voltages inputted level of voltages inputted to the D/A converter circuit. 
 
   
   
     2. A driving method of a display device according to  claim 1 ,
 wherein the m and the n are integers equal to or larger than 2 and satisfy m>n. 
 
   
   
     3. A driving method of a display device according to  claim 1 ,
 wherein the display device comprises thresholdless antiferroelectric mixed liquid crystal indicating electro-optical characteristic of V-shape. 
 
   
   
     4. A driving method of a display device according to  claim 1 ,
 wherein the m is 8 and the n is 2. 
 
   
   
     5. A driving method of a display device according  claim 1 ,
 wherein the m is 12 and the n is 4. 
 
   
   
     6. A driving method of a display device comprising:
 converting n bit digital video data of m bit digital video data into n bit digital video data for voltage gray scale; and 
 expressing gray scale by using n bit data for voltage gray scale information and (m−n) bit data for time ratio gray scale information, 
 wherein each of a voltage level for the voltage gray scale is as (VH−VL)/2 n , where VH is the highest voltage level of voltages inputted to a D/A converter circuit and VL is the lowest voltages inputted level of voltages inputted to the D/A converter circuit, and 
 wherein an image is displayed by an image gray scale of (2 m −(2 m−n −1)) patterns. 
 
   
   
     7. A driving method of a display device according to  claim 6 ,
 wherein the m and the n are integers equal to or larger than 2 and satisfy m>n. 
 
   
   
     8. A driving method of a display device according to  claim 6 ,
 wherein the display device comprises thresholdless antiferroelectric mixed liquid crystal indicating electro-optical characteristic of V-shape. 
 
   
   
     9. A driving method of a display device according to  claim 6 ,
 wherein the m is 8 and the n is 2. 
 
   
   
     10. A driving method of a display device according  claim 6 ,
 wherein the m is 12 and the n is 4. 
 
   
   
     11. A driving method of a display device comprising:
 inputting analogue video data to an A/D converter circuit; 
 converting the analogue video data to digital video data by the A/D converter circuit; 
 converting n bit digital video data of m bit digital video data into n bit digital video data for voltage gray scale; 
 inputting the n bit digital video data to a D/A converter circuit; 
 converting the n bit digital video data to n bit analogue video data; and 
 expressing gray scale by using the n bit analogue video data for voltage gray scale information and (m−n) bit digital video data for time ratio gray scale information, 
 wherein each of a voltage level for the voltage gray scale is as (VH−VL)/2 n , where VH is the highest voltage level of voltages inputted to a D/A converter circuit and VL is the lowest voltages inputted level of voltages inputted to the D/A converter circuit. 
 
   
   
     12. A driving method of a display device according  claim 11 ,
 wherein the m and the n are integers equal to or larger than 2 and satisfy m>n. 
 
   
   
     13. A driving method of a display device according to  claim 11 , wherein the display device comprises thresholdless antiferroelectric mixed liquid crystal indicating electro-optical characteristic of V-shape. 
   
   
     14. A driving method of a display device according to  claim 11 ,
 wherein the m is 8 and the n is 2. 
 
   
   
     15. A driving method of a display device according  claim 11 ,
 wherein the m is 12 and then is 4. 
 
   
   
     16. A driving method of a display device comprising:
 inputting analogue video data to an A/D converter circuit; 
 converting the analogue video data to digital video data by the A/D converter circuit; 
 converting n bit digital video data of m digital video data into n bit digital video data for voltage gray scale; 
 inputting the n bit digital video data to a D/A converter circuit; 
 converting the n bit digital video data to n bit analogue video data; and 
 expressing gray scale by using the n bit analogue video data for voltage gray scale information and (m−n) bit digital video data for time ratio gray scale information, 
 wherein each of a voltage level for the voltage gray scale is as (VH−VL)/2 n , where VH is the highest voltage level of voltages inputted to a D/A converter circuit and VL is the lowest voltages inputted level of voltages inputted to the D/A converter circuit, and 
 wherein an image is displayed by an image gray scale of (2 m −(2 m−n −1)) patterns. 
 
   
   
     17. A driving method of a display device according  claim 16 ,
 wherein the m and the n are integers equal to or larger than 2 and satisfy m>n. 
 
   
   
     18. A driving method of a display device according to  claim 16 ,
 wherein the display device comprises thresholdless antiferroelectric mixed liquid crystal indicating electro-optical characteristic of V-shape. 
 
   
   
     19. A driving method of a display device according to  claim 16 ,
 wherein the m is 8 and the n is 2. 
 
   
   
     20. A driving method of a display device according  claim 16 ,
 wherein them is 12 and the n is 4.